The present invention relates generally to connecting an external peripheral to a universal serial bus (USB) port on a computer, and more specifically, to a system and apparatus for connecting a digitally controlled display peripheral to the USB port of a computer or a USB hub.
The various capabilities and features of external computer peripherals sometimes must be accessed through a series of computer system components. In the current age of personal computer use, these components may be designed and produced by different companies and achieve some level of compliance to interchangability standards. At the same time, these non-standard components may not support access to all of the features of a particular manufacturers external peripheral. All such component manufactures make market related choices regarding which features and capabilities they choose to support. Ultimately, special niche markets and external peripherals that have applications to these markets, may not get supported by such component manufacturers.
A specific example concerns computer displays and their characteristics. Display peripheral vendors design advanced capability that often is not supported by operating system vendors or graphic card vendors. Typically, without support from such interim solution providers, advanced capabilities, which may not be mass market oriented, cannot find third party implementation for control software or interface means. Users must take additional steps to provide access to the advanced capability that increases cost or compromises accessibility.
For example, external display peripherals benefit from digital control from an attached host computer. While it is well known that photopic and/or calorimetric measurement and adjustment of display parameters can result in improvement of display capability, effecting such adjustment across various operating system software, third party software, and graphic cards can be quite complicated and may not be possible based on the capabilities of each.
Recent standards regarding implementation of display characteristics have been published by the Video Electronics Standards Association (VESA) committee, and are implemented by several display peripheral vendors. The VESA committee is a modem day standards organization active in developing standards for use in the display peripherals regardless of the specific display technology and across many communication protocols and interfaces. Standards organizations have allowed for many popular features to be implemented by multiple manufacturers in a standard fashion in response to end user plug and play needs.
Most modern display devices include digital control features such as the capability to power down, at least partially, after a period on non-use in order to save energy and increase the useful product life. At least some modern devices also allow the identification of manufacturer make and model via a digital electronic interface so that host systems can automatically detect and operate the peripheral in optimum fashion.
Access to these controls is allowed through signals that are transmitted through the cable that connects the display peripheral to computer. Often the computer may have a supplemental graphics card included to which the cable connects. This graphics card and its controls must support or pass functions for them to be available downstream.
In the specific area of digital electronic control of display devices, such as cathode ray tubes (CRT""s), liquid crystal displays (LCD""s), and Plasma Display Panel (PDP""s), VESA has developed and continues to issue revisions to the xe2x80x9cDisplay Data Channelxe2x80x9d (xe2x80x98DDCxe2x80x99) specifications. The specification of these control signals includes the communication protocol, connector style, signal definition and pin assignments in order to conform to the particular version of the standard. A recent communication protocol known as xe2x80x9cI2Cxe2x80x9d has been adopted to communicate these DDC commands to the graphic host, often a graphics card internal to the host computer.
Typically, the graphic host, whether it be an add in graphics display card for the host or a built in graphics capability to the motherboard of the host computer, interfaces with the display device over this protocol to receive and transmit digital commands which control many aspects regarding how data is displayed by the display peripheral. The graphics host must communicate through operating system software to the host computer to allow such settings to be selected, either by user interaction or automatic plug and play selection through host computer. Advances in wireless and Internet communications also provide remote access and communication.
In an environment where multiple manufacturers supply various components of computer systems, such as graphic cards, host computers, operating system software, and display devices the benefits of such popular standards to the end user are clear. Users benefit from standard implementation of common features because component selection is competitive and plug and play operation is possible once all manufacturers comply with the standard. However, less popular or more complex functions may not get adopted by such industry based standards organizations or incorporated by the manufacturers.
For example, display manufacturers may choose to implement features in addition to those that have been adopted by the standard organizations to give their current products a competitive market edge over other manufacturers. Additionally, since VESA consists of industry members from profit based firms, there may be competitive reasons for one manufacturer to favor, promote, or not disclose some enhancement to the DDC specification.
One such example of this is the scale display command. This is a generic command that scales the geometry of the electronic display so that it fits the available screen real estate. The standards organization has defined this command both for horizontal and vertical directions. At least one display peripheral manufacturer has implemented this command in both the standards fashion as well as in its own format, referring to it as a xe2x80x98zoomxe2x80x99 command, possibly perceiving this presentation to more intuitive to the user. Since the DDC format is well known by anyone skilled in the art, detecting the byte order of the combined command, which sets both the vertical and horizontal standardized commands simultaneously, is not difficult.
A disadvantage of the present methods by which VESA standards are implemented is that many manufacturers must support a feature of the DDC to allow end users to remotely access its settings. Typically a command to set a color related aspect of the display device is set directly at the push button control panel of the display peripheral or through user interface to the host computer. If the particular display implements a manual control panel the user can, at the display manufacturer""s option, set these parameters locally, but not remotely. Often the manual control panel feature carries substantial cost to the display peripheral manufacturer and it is difficult to cost justify the inclusion for markets wherein only a small portion of users make use of such features. In order for the user to set such features at the host computer, both the operating system and the graphic host must support calls to the feature contained in the display device.
In the prior example regarding geometry xe2x80x98zoomxe2x80x99 of the display, the user could only set this parameter remotely if the operating system software or its extensions allowed the user to enter the command. The graphic host would also have to relay this command to the display peripheral. Manufacturers often use graphic display cards or third party graphic host devices added into the host computer that are unable or unwilling to support every nonstandard command from every display peripheral manufacturer. Ultimately, a disadvantage to end users is that only standard commands are routinely available for setting display parameters remotely or that costs will be higher than it might otherwise be for such features.
There have been several attempts to reduce the aforementioned problems. U.S. Pat. No. 5,717,428 (""428) describes a keyboard with some electronics and cabling to support various types of computers. The ""428 invention is intended as a keyboard that may be used remotely from a computer and store the typed input. Upon physical connection to a host computer, the buffer is transmitted to the computer. As the keyboard is designed for different types of computers, there is appropriate conversion circuitry to enable the transmission and cables that support the host computer.
Another keyboard patent, U.S. Pat. No. 5,841,424, discloses a keyboard that serves as a USB docking station. The keyboard houses the necessary translation circuitry and multiple connectors.
U.S. Pat. No. 5,729,573 (""573) discloses a system for increased transmission rates via a pair of parallel cables and associated circuitry. This invention encompasses a separate central processing unit (CPU) with memory to control parallel data transfer between a host computer and it computer peripheral devices.
U.S. Pat. No. 5,838,926 (""926) is a network methodology for organizing computer peripherals on the network. The most appropriate peripheral can be selected among the various networked peripherals.
A USB converter device is described in U.S. Pat. No. 5,935,224, wherein non-USB peripheral devices can be connected and communicate with the host computer via a USB port. The ""224 patent primarily focuses on game ports, but discusses a converter that attaches to a cable and has a data acquisition interface, a microcontroller, a USB engine and a USB transceiver.
However, none of the prior art designs have adequately addressed accessing unique display peripheral controls through a USB interface. What is needed is a cost-effective device that can provide access to digital display peripheral controls that are not otherwise accessible. Such a device should permit integration into existing designs and also allow usage by existing display peripherals. The interface should employ a bypass means to permit existing controls and only operate when the special controls are required or requested.
In accordance with the present invention, an apparatus and system for the control of and communication with a DDC display peripheral via USB is disclosed. In one preferred embodiment, a cable is defined for use in coupling a display peripheral to a computer. The cable passes all typical display signals from the display peripheral to the computer through typical means. The cable can be fixedly attached at the display end or have a plug and mating receptacle. The cable also has a means of providing a USB connection either by a jumper cable with a male USB connector, or a female USB connection.
An alternate embodiment is an adapter that attaches to the existing display peripheral cable and has the necessary mating connectors for USB. The adapter can connect at either end of the cable when the cable is not fixedly attached to the display peripheral device, making the USB interface accessible at either the computer or the display peripheral device.
The present invention is aimed at providing access to display controls allowed through signals that are transmitted through the cable that connects the display peripheral to the computer. The display control signals are broken out of the typical information chain and converted to an alternate communication protocol.
A circuit is embedded in the device that receives USB signals and messages from the host CPU via USB and translates these USB signals and messages into DDC signals and messages for transmission to the display peripheral. The same circuit receives DDC signals and messages from the display peripheral and translates them into USB signals and messages for the host CPU. In one embodiment display peripheral connection to the USB port or hub is provided by a third lead or connector on the display peripheral/computer cable. Internal to the USB circuitry is a microprocessor that acts as a universal serial bus transceiver and controller that operates to change the format of data and provide data exchange control from display peripheral to the computer. This allows display peripheral characteristics to be controlled by user activated software which may be resident on the computer or remotely on a network, or via the Internet or wireless means.
There are many benefits to the implementation of such USB processing. The display peripheral manufacturer benefits because the advanced display control features, both standard and proprietary, can be implemented without support from operating system companies and graphic card companies. Time to market is decreased because there is no need to work with other companies to implement the advanced controls in the operating system of graphics cards. The intellectual property protection is improved because proprietary information and trade secrets do not have to be revealed to other parties. Additionally, there is no need for the display peripheral manufacturer to include a costly manual pushbutton control panel within each display peripheral, as the computer to host cable contains all requirements. The benefit to the customer or user is twofold, a greater field of choice to access the advanced display options across all user seats, and access to an increased number of solution providers who may offer them greater selection.
There are instances wherein display peripheral manufacturers depart from the accepted standard connector and/or pin arrangements. In these situations, alternative embodiments include adapters that encompass with internal wiring that alters the signal carried by one or more pins. These display peripherals include relatively high-resolution monochrome display peripherals in use today for medical imaging as well as some color display peripherals uniquely dedicated to non-PC systems, for example, those serving the UNIX operating systems.
Alternate embodiments are provided as adapters containing a connection to, or port for, other types of sensors, for example a coincidence sensor, that are used for measuring and subsequently correcting R, G, B electron beam alignment of color display devices.
Alternate embodiments are provided as cables or adapters that enable connection of devices in which the invention""s microprocessor is used to provide either in-part or in-total the processing power of the external device. An example is the connection of an external light sensor which gains some signal processing or manipulation by the imbedded cable/adapter microprocessor.
The present invention allows alternate access to the DDC signals. The signals xe2x80x98pass throughxe2x80x99 the converter to allow conventional access by whatever means might otherwise be employed, however, and of main interest in high end display imaging, the signals are also accessible via the Universal Serial Bus. The converter includes translation means from the I2C protocol to the USB protocol and communications means to transmit and receive in both protocols as required to read and set parameters within the display.
Physically, the converter resides between the graphic host and the display peripheral, either integrated in the display peripheral cable or as an adapter that mates to the cable and connects to either the display peripheral or graphic host. Branching off from this circuit is a USB compatible wire bundle and plug that mates to a USB port or hub in standard fashion. The converter may contain additional input/output (I/O). In a preferred embodiment the circuit is built into a VGA display cable and contains no other inputs or outputs. In an alternate embodiment, the circuit is built into a small box or adapter where it may also have an additional plug to connect a light measuring device capable of measuring and returning data regarding the display.
Regardless of whether the device utilizes light measurement data, the DDC signals after conversion from I2C are available to the host. And, these DDC signals are also accessible, with appropriate connection, to the Internet through the USB connection of the converter. The DDC information can be sent from the Internet or host to the display device through the USB protocol via the converter. This allows for remote control of digital display devices, both in terms of asset control as well as display standardization. This satisfies a key to successful remote hardcopy color printingxe2x80x94successful color soft proofing at multiple sites. The DDC information can be transmitted to multiple sites so that the display characteristics of the original site can be used to re-create the original display on other systems.
Additionally, the present device also has applications in insuring monochrome images for medical imaging applications among others, are similarly displayed in multiple locations where it is necessary to optimize the display with respect to the maximum number of shades of gray that are displayed. Providing Internet access permits a group of persons to coordinate various display peripheral displays and different host systems to adhere to the parameters of single display so all users see the same image.
One of the unique aspects of the present invention is that some signals, but not all, pass through the converter circuit to be otherwise accessible by the host, or graphic host in otherwise normal fashion. This feature derives from the manner in which the circuit is powered and whether all ports from the circuit are connected to the intended port. Electronic switches are powered closed in order to achieve electronic continuity on lines that may not otherwise be accessed by the host. The power to close these switches must be available from the non-USB host connection since there is no guarantee that a USB port is available. This ensures the cable or adapter will allow normal R, G, B operation of a display peripheral even though the USB port is not connected.
The present invention accomplishes the selective passing of signals in the disclosed circuit by allowing the switches to be powered by any potential power or signal line. Power to initialize the processor is derived only from the USB port. Thus, if the converter is not powered by the USB source, the processor is not active, but the switches are powered closed allowing normal host to display peripheral signals to xe2x80x98pass throughxe2x80x99 the circuit. Additionally, when the processor is powered and active, the switches are normally closed. Since the display peripheral behaves as a slave device, it only transmits data when polled. In this way the switches can be opened at known times to allow communication directly from converter to display peripheral and USB port which is not presented to the graphic host.
Another purpose of the present invention is to allow identification of display peripheral capabilities through such a converter. Since it is possible to remotely poll display devices and remotely set parameters in display devices, it is also possible to identify display peripheral type and capability remotely to the extent unique features can be identified. For example, if only one family of display peripherals from one manufacturer responds to a command used to set xe2x80x98zoomxe2x80x99 on its displayable screen area, rather than setting vertical and horizontal scale parameters separately, then by polling, setting, and re-polling, it is possible to identify that display peripheral type remotely. Additionally, if other known differences exist between models within that manufacturers display peripheral family, then it is also be possible to remotely detect model type. Additionally it is possible to identify individual display devices should unique identification means be known such as a serial number. Although this type of identification is known utilizing other means, it is an object of the present invention to the extent that display devices are identified through a DDC/USB converter.
An additional object is to provide remote access and communications to the display via wireless and Internet communications. The technological improvements in the communications arena enable high-speed and secure communications over the Internet to permit users to coordinate displayed images.
The present invention converts DDC signals from and to USB protocol and allows access of the translated DDC signals through a USB port connection. Support requirements from third parties are thus greatly simplified because they can now access and control signals that are unsupported and would be too costly to implement. The graphics host and operating system need not support any DDC standards, as the USB interface can control the display peripheral. The USB protocol and connection means must be present in the host computer, but this is a widely accepted standard. Legacy issues for previous I/O options on computers have been well documented by prior art that converts peripherals meant for one communication protocol to the more modem USB protocol. However, much of the focus of the prior art involved easing change over requirements as the new serial bus came into widespread use. The present invention utilizes the USB protocol to circumvent support requirements from manufactures that have not implemented DDC support, or have implemented alternate variations of DDC support.
One object of the invention is a signal converter for converting Uniform Serial Bus (USB) communication and display peripheral communication between a host and a display peripheral, comprising a power management section for providing power to the signal converter, a connection between the display peripheral and the host, wherein the connection also couples to a USB interface. There is a switching section for maintaining standard communications between the display peripheral and the host, wherein the switching section switches to the USB interface allowing communication between the host and the display peripheral through the USB interface. There is also a controller for managing the switching section and translating the USB communication to the display peripheral communication and translating display peripheral communication to the USB communication.
A further object is a signal converter, wherein the display peripheral communication complies with Video Electronics Standards Association (VESA) Display Data Channel (DDC) communications protocol.
Additionally, another object is a signal converter, wherein the switching section is in a default position for maintaining the standard communications.
An object includes a signal converter, wherein the power management section employs power scavenging capability to extract power from multiple signal lines as well as standard sources of power.
A further object is a signal converter, wherein the USB interface is integrated into a cable connecting between the display peripheral and the host. Alternatively, a signal converter wherein the USB interface is an adapter between a cable connecting between the display peripheral and the host, and wherein the adapter mates to an end of the cable.
Yet another object is for a signal converter, further comprising a colorimeter, wherein the colorimeter communicates with the host and is used to establish colorimetry of the display peripheral.
An object of the invention is a converter for enabling a computer display peripheral to connect through a USB interface to a host computer to enable some features to be controlled, comprising a cable with non-USB connections to the computer display peripheral and the host computer, and a USB connection interconnected to the cable. There is a translating means for communicating between the computer display peripheral and the host computer, as well as a controller coupled to the translating means, wherein the controller manages an exchange of data between the computer display peripheral and the host computer.
An additional object is a converter, further comprising a user interface to implement colorimetry adjustments to the display peripheral.
Further object includes a converter, further comprising a user interface to implement geometry adjustments to the display peripheral.
Yet another object is a converter, further comprising a user interface allowing manual adjustment of the display peripheral. Alternatively, a converter, wherein the converter operates under program control.
An object of the invention is a method for communicating with a display peripheral through a USB interface, comprising the steps of linking the USB interface to a connection between the display peripheral and a computer, processing bi-directional communications between the display peripheral and the computer in a normal fashion, switching a converter to a master mode when the converter is sent USB commands from the computer, translating USB communications from the computer to the display peripheral when in the master mode, translating display peripheral communications from the display peripheral to the computer when in the master mode, and changing display peripheral settings based upon status and commands when in the master mode from the USB communications and from the display peripheral communications.
Additional object includes a method, wherein the step of linking is an adapter connecting to the connection between the display peripheral and the computer, wherein the connection is a cable. Another object is for a method, wherein the step of linking is an integrated connection to the connection between the display peripheral and the computer, wherein the connection is a cable.
Yet a further object is a method, wherein the step of linking the USB interface is done by attaching a cable between the computer and the display peripheral, wherein the cable has embedded electronics and the USB interface.
And an even further object is for a method, wherein the method for communicating is via software control over a local network. Additionally, a method wherein the method for communicating is via software control over an Internet connection.
A final object is for a method, further comprising a step of allowing a user interface at the computer.
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description, wherein only a preferred embodiment of the invention is described, simply by way of illustration of the best mode contemplated for carrying out the invention. As will be realized, the invention is capable of other and different embodiments, and its several details are capable of modifications in various obvious respects, all without departing from the invention.